/*
 * Copyright 2021 The Backstage Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * A middleware that modifies the behavior of an ongoing fetch.
 *
 * @public
 */
export interface FetchMiddleware {
  /**
   * Applies this middleware to an inner implementation.
   *
   * @param next - The next, inner, implementation, that this middleware shall
   *               call out to as part of the request cycle.
   */
  apply(next: typeof fetch): typeof fetch;
}
